Investigation of a reconfigurable dual notched UWB antenna by conceptual circuit model and time-domain characteristics

In this paper, an ultra-wideband (UWB) antenna with reconfigurable performance is proposed. The antenna consists of a U-shaped radiation patch and a ground plane which is symmetric with the edge of the radiation patch. By using two open-ended L-shaped slots (OEL-S) and one U-shaped slot Defected Ground Structure, the dual notched bands at 3.5 GHz for WiMAX and 5.5 GHz for WLAN are obtained. Three switches are embedded in both L-shaped and U-shaped slots in order to achieve four switchable modes by switching them between ON and OFF states. There are three modes that the antenna can be switched in, which are dual, single and no band-notched modes. The measured result illustrates that the operation frequency band is from 2.7 GHz to 12 GHz (VSWR < 2). Moreover, the conceptual circuit model and time-domain characteristics of the antenna are also proposed to investigate the dual band-notched performance.